The ground-breaking Star Wars trilogy may have taken place in a galaxy far, far away, but a new book has revealed that the origins of famous characters such as R2D2 and Chewbacca were very much of this world.

C-3PO and R2D2

It also suggests that director George Lucas originally intended Star Wars to be the third of a trilogy of films which would secretly protest against the Vietnam War.Referring to the origins of some of the films' most memorable characters, the book – called How Star Wars Conquered the Universe – reveals that the names of the Wookiees and the robot R2D2 date back to notes made by Lucas years before filming began.While making his first film, the 1971 science fiction feature THX 1138, Lucas was working with voice actor DJ Terry McGovern, who brought his friend and fellow Army reservist Bill Wookey along to the studio.